Safety device of battery

Abstract

A safety device of a battery including a pressure releasing unit provided at a cell and the battery, in which the pressure releasing unit is configured to release an internal pressure within the cell when the internal pressure of the cell exceeds a predetermined set pressure. Also included is a space member covering the pressure releasing unit and configured to form an empty space around the pressure releasing unit such that when the internal pressure of the cell exceeds the predetermined set pressure, the released internal pressure is released into the empty space formed by the space member.

1. A safety device of a battery, comprising:
 a pressure releasing unit provided at a cell of the battery, said pressure releasing unit configured to release an internal pressure within the cell when the internal pressure of the cell exceeds a predetermined set pressure; 
 a protection circuit assembly coupled to a surface of the cell provided with the pressure releasing unit; 
 a space forming member formed of a first resin and covering the pressure releasing unit; and 
 an injection-molded cover member formed of a second resin and configured to encompass the space forming member and the protection circuit assembly, 
 wherein the space forming member is configured to form an empty space around the pressure releasing unit such that when the internal pressure of the cell exceeds the predetermined set pressure, the released internal pressure is released into the empty space formed by the space member, and 
 wherein a melting temperature of the first resin is higher than a melting temperature of the second resin so as to prevent molten material of the cover member from being introduced into the empty space. 
 
     
     
       2. A safety device of a battery, comprising:
 a pressure releasing unit provided at a cell of the battery, said pressure releasing unit configured to release an internal pressure within the cell when the internal pressure of the cell exceeds a predetermined set pressure; 
 a space forming member covering the pressure releasing unit and configured to form an empty space around the pressure releasing unit such that when the internal pressure of the cell exceeds the predetermined set pressure, the released internal pressure is released into the empty space formed by the space member; 
 a protection circuit assembly coupled to a surface of the cell provided with the pressure releasing unit; 
 an injection-molded cover member encompassing the space forming member and the protection circuit assembly; 
 a through hole formed through the cover member and the space forming member and configured to allow the empty space formed around the pressure releasing unit to communicate with an outside of the cover member; and 
 an auxiliary pin inserted in the through hole and configured to be pushed out of the through hole when the pressure is released into the empty space. 
 
     
     
       3. The device of  claim 1 , wherein the first resin comprises liquid crystalline polyester (LCP). 
     
     
       4. The device of  claim 1 , wherein the pressure releasing unit includes a thin film portion configured to break or tear when the internal pressure of the cell exceeds the predetermined set pressure. 
     
     
       5. The device of  claim 4 , wherein a groove is formed at an outer surface of the cell to form the thin film portion of the pressure releasing unit. 
     
     
       6. The device of  claim 4 , wherein a groove is formed at an inner surface of the cell to form the thin film portion of the pressure releasing unit. 
     
     
       7. The device of  claim 1 , wherein the space forming member comprises a space forming cap covering the pressure releasing unit. 
     
     
       8. The device of  claim 1 , wherein the space forming member comprises an injection-molded space portion formed in the cover member and being placed at a position facing the pressure releasing unit. 
     
     
       9. A battery for a mobile communication terminal, comprising:
 a battery cell configured to provide a power source for the mobile terminal; 
 a protection circuit assembly attached to a surface of the battery cell and configured to stabilize the power source within the battery cell when the battery is charged or discharged; 
 a cover member formed of a first resin and configured to cover the protection circuit assembly and to couple the protection circuit assembly to the battery cell; 
 a pressure releasing unit provided at a cell of the battery, said pressure releasing unit configured to release an internal pressure within the cell when the internal pressure of the cell exceeds a predetermined set pressure; and 
 a space forming member formed of a second resin and configured to cover the pressure releasing unit and to form an empty space around the pressure releasing unit such that when the internal pressure of the cell exceeds the predetermined set pressure, the released internal pressure is released into the empty space formed by the space member, 
 wherein a melting temperature of the second resin is higher than a melting temperature of the first resin so as to prevent molten material of the cover member from being introduced into the space. 
 
     
     
       10. A battery for a mobile communication terminal, comprising:
 a battery cell configured to provide a power source for the mobile terminal; 
 a protection circuit assembly attached to a surface of the battery cell and configured to stabilize the power source within the battery cell when the battery is charged or discharged; 
 a cover member configured to cover the protection circuit assembly and to couple the protection circuit assembly to the battery cell; 
 a pressure releasing unit provided at a cell of the battery, said pressure releasing unit configured to release an internal pressure within the cell when the internal pressure of the cell exceeds a predetermined set pressure; 
 a space forming member covering the pressure releasing unit and configured to form an empty space around the pressure releasing unit such that when the internal pressure of the cell exceeds the predetermined set pressure, the released internal pressure is released into the empty space formed by the space member; 
 a through hole formed through the cover member and the space forming member and configured to allow the empty space formed around the pressure releasing unit to communicate with an outside of the cover member; and 
 an auxiliary pin inserted in the through hole and configured to be pushed out of the through hole when the pressure is released into the empty space. 
 
     
     
       11. The battery of  claim 10 , wherein a material of the space forming member comprises liquid crystalline polyester (LCP). 
     
     
       12. The battery of  claim 9 , wherein the pressure releasing unit includes a thin film portion configured to break or tear when the internal pressure of the cell exceeds the predetermined set pressure. 
     
     
       13. The battery of  claim 12 , wherein a groove is formed at an outer surface of the cell to form the thin film portion of the pressure releasing unit. 
     
     
       14. The battery of  claim 12 , wherein a groove is formed at an inner surface of the cell to form the thin film portion of the pressure releasing unit. 
     
     
       15. The battery of  claim 9 , wherein the space forming member comprises a space forming cap covering the pressure releasing unit. 
     
     
       16. The battery of  claim 9 , wherein the space forming member comprises an injection-molded space portion formed in the cover member and being placed at a position facing the pressure releasing unit.